Trench junction barrier controlled Schottky

ABSTRACT

A Schottky diode includes at least a trenched opened in a semiconductor substrate doped with a dopant of a first conductivity type wherein the trench is filled with a Schottky junction barrier metal. The Schottky diode further includes one or more dopant region of a second conductivity type surrounding sidewalls of the trench distributed along the depth of the trench for shielding a reverse leakage current through the sidewalls of the trench. The Schottky diode further includes a bottom-doped region of the second conductivity type surrounding a bottom surface of the trench and a top-doped region of the second conductivity type surrounding a top portion of the sidewalls of the trench. In a preferred embodiment, the first conductivity type is a N-type conductivity type and the middle-depth dopant region comprising a P-dopant region.

This patent application is a Continuation in Part (CIP) application of aco-pending application with a Ser. No. 11/056,345 filed by a commonInventor of this application on Feb. 11, 2005. The Disclosures made inthat application is hereby incorporated by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates generally to the semiconductor power devices. Moreparticularly, this invention relates to an improved and novelmanufacturing process and device configuration for providing the MOSFETdevice with shielded trench gates with cells provided with Schottkysource contact for improving performance of high frequency powerswitching, H-bridge and synchronization rectification applications.

2. Description of the Related Art

As the applications of Schottky diodes become more widespread,particularly for reducing the power consumption and increasing theswitching speed, it becomes even more important to improve the deviceconfiguration and manufacturing processes to reduce the production costsof the Schottky rectifying devices. One particular importantconsideration is the reduction of the surface areas on the semiconductorsubstrate occupied by the Schottky diodes. Reduction of the surface-areautilization of the Schottky diodes provides a key to reduce themanufacturing costs and to further miniaturize the size and shape ofelectronic devices for achieving portability and functionalityenhancements. However, in order to achieve the purpose of surfaceutilization while maintaining current conducting areas, the Schottkydiodes are sometimes implemented by filling trenches with a barriermaterial. The trench Schottky diode configuration leads to anothertechnical difficulty due to the breakdown vulnerability at trenchcorners where there are sharp edges. In order to overcome suchdifficulties, a round trench bottom is necessary and that causes theproduction cost to increase. Due to these reasons, a person of ordinaryskill in the art of designing and manufacturing devices includingSchottky diodes is still confronted with the technical difficulties andlimitations that a reduction of production cost cannot easily achieved.

The Schottky diode has been used to replace PN diodes in manyapplications. The low forward drop of the Schottky diode in the forwardconduction mode reduces the power dissipation of the device. Theconduction of the Schottky is through majority carrier, so minoritycarrier charge storage effects do not occur in the switchingcharacteristics of the device. Therefore the Schottky diode is apreferred over the PN junction diodes in many power applications. FIG.1A shows a typical Schottky diode where a Schottky barrier metal iscontacted to a n-type silicon. The P+ junctions are placed at the edgeof the barrier metal contact areas to eliminate the premature breakdownof the device. The forward voltage of the diode is directly proportionalto the Schottky barrier height of the metal. It is then desirable to uselow Schottky barrier metal to make the diode in order to reduce theconduction loss of the diode. However, the leakage current of theSchottky in the reverse blocking mode is also determined by the Schottkybarrier height. Low Schottky barrier height will give rise to higherleakage current in the reverse blocking operation of the diode.

In order to reduce the reverse leakage of the Schottky diode, P-typejunctions are placed in the silicon as shown in FIG. 1B. In the reverseblocking mode, the n-silicon is at a higher potential with respect tothe Schottky barrier metal. The PN junction is also reverse bias. Thedepletions from two adjacent p-type junctions merged and shield thesurface Schottky barrier from the high reverse voltage thus reduce theleakage current of the diode. The disadvantage of the JBS is the reducedSchottky surface area from the p-type junctions. For higher breakdownvoltage Schottky diode, deeper p-type junction is usually required.Deeper junction also has more lateral diffusion. The Schottky areautilization could be quite low for the high breakdown voltage JBS. Analternative way to shield the Schottky barrier from the reverse voltageis the Trench MOS Barrier Schottky as shown in FIG. 1C. With the trenchSchottky barrier, the depletions from surrounding the lower portions ofthe trenches pinch off and shield the Schottky barrier junction on topthe mesa. The shape of the trenches affects the breakdown of thedielectric in the trenches. Rounding the bottom and top corners arerequired to reduce the leakage of the TMBS. The rounding of the sharpcorners requires extra process steps and specialized equipment and allthese requirements cause an increase in the production costs.

Therefore, a need still exists in the art of implementing the Schottkydiodes in the electronic device including the power semiconductordevices to provide new device configuration and manufacturing method inconfiguring and manufacturing the Schottky diodes to overcome andresolve the above discussed problems and limitations.

SUMMARY OF THE PRESENT INVENTION

It is therefore an aspect of the present invention to provide a new andimproved Schottky diode with the junction barrier metal deposited in thetrenches with dopant regions for preventing the reverse leakage currentdisposed on the sidewalls of the trenches and at surrounding the top andbottom corners of the trenches. The depletion from the PN junctionsprovides the function to shield the Schottky barrier from the reversevoltage. The silicon area utilization is greatly improved and therequirement of a round trench bottom is eliminated such that the abovediscussed limitations and difficulties of the convention Schottky isresolved.

Another aspect of this invention is to provide new and improved Schottkydevice configuration to achieve the purpose to improve the silicon areautilization of the junction barrier Schottky (JBS) by forming theSchottky junction on the sidewall of trench.

Another aspect of this invention is to provide new and improved Schottkydevice configuration that in addition to improve the silicon areautilization of the junction barrier Schottky (JBS) by forming theSchottky junction on the sidewall of trench, the junction barrierSchottky (JBS) formed along the trench sidewalls is combined andintegrated with either planar or trenched MOSFET devices to improved theperformances of the semiconductor power devices.

Another aspect of this invention is to provide new and improved Schottkydevice configuration that in addition to improve the silicon areautilization of the junction barrier Schottky UBS) by forming theSchottky junction on the sidewall of trench, the Schottky device is nowmanufactured with simplified manufacturing processes with reducedprocess complexity. Furthermore, the simplified manufacturing processesare implemented with standard processing steps as that commonlyimplemented for typical MOSFET power device manufacture thus greatlyreduce the production cost and can be conveniently combined andintegrated with a standard MOSFET device.

Briefly in a preferred embodiment this invention discloses a Schottkydiode that includes at least a trenched opened in a semiconductorsubstrate doped with a dopant of a first conductivity type wherein thetrench is filled with a Schottky junction barrier metal. The Schottkydiode further includes a dopant region of a second conductivity typesurrounding sidewalls of the trench near the top and at the bottom ofthe trench for shielding a reverse leakage current through the sidewallsof the trench. In a preferred embodiment, the first conductivity type isa N-type conductivity type and the middle-depth dopant region comprisinga P-dopant region.

In another preferred embodiment this invention discloses a Schottkydiode that includes at least a trenched opened in a semiconductorsubstrate doped with a dopant of a first conductivity type wherein thetrench is filled with a Schottky junction barrier metal. The Schottkydiode further includes one or more dopant regions of a secondconductivity type surrounding sidewalls of the trench distributed alongthe depth of the trench for shielding a reverse leakage current throughthe sidewalls of the trench. The Schottky diode further includes abottom-doped region of the second conductivity type surrounding a bottomsurface of the trench and a top-doped region of the second conductivitytype surrounding a top portion of the sidewalls of the trench.

Another embodiment of this invention includes a semiconductor devicethat includes a Schottky diode includes at least a trenched opened in asemiconductor substrate doped with a dopant of a first conductivity typewherein the trench is filled with a Schottky junction barrier metal. Thesemiconductor device further includes a dopant region of a secondconductivity type surrounding sidewalls of the trench at the top and ofthe trench for shielding a reverse leakage current through the sidewallsof the trench. The semiconductor device further includes a MOSFET deviceintegrated with the Schottky diode configured as a trench junctionbarrier Schottky (TJBS) diode. The MOSFET device is integrated with andmanufactured simultaneously with the Schottky diode configured as atrench junction barrier Schottky (TJBS) diode. In a preferredembodiment, the MOSFET is a planar MOSFET device integrated andmanufactured simultaneously with the Schottky diode wherein the planarMOSFET further includes a body region extending to and surrounding a topportion of the trench of the Schottky diode for shielding the reverseleakage current through the sidewalls of the trench. In anotherpreferred embodiment, the MOSFET is a trench MOSFET device integratedand manufactured simultaneously with the Schottky diode configured as atrench junction barrier Schottky (TJBS) diode wherein the trench MOSFETfurther comprising trenched gates disposing around the trench of theTJBS diode. The trench MOSFET device further includes a body regionextending to and surrounding a top portion of the trench of the Schottkydiode for shielding the reverse leakage current through the sidewalls ofthe trench.

In an exemplary embodiment, this invention further discloses a method ofmanufacturing a trench junction barrier controlled Schottky device. Themethod includes steps of opening a trench in a semiconductor substrateof a first conductivity type to a middle depth and implanting a dopantof a second conductivity type at the bottom of the trench by implantingat substantially zero degree into the trench. The method furtherincludes a step of forming a dopant region of the second conductivitytype surrounding the sidewalls of the trench near the top surface of thetrench for shielding a reverse leakage current through the sidewalls ofthe trench. Then the method proceeds with another step filling thetrench with a Schottky barrier metal. In a preferred embodiment, thestep of opening a trench in a semiconductor substrate of a firstconductivity type is a step of opening the trench in a N-typesemiconductor substrate and the second dopant region is a P-type.

In another exemplary embodiment, this invention further discloses amethod of manufacturing a trench junction barrier controlled Schottkydevice. The method includes steps of opening a trench in a semiconductorsubstrate of a first conductivity type to a middle depth and implantinga dopant of a second conductivity type to form a middle-depth dopantregion of the second conductivity type. The method further includes astep of opening the trench to a full trench depth with the middle-depthdopant region surrounding sidewalls of the trench at about amiddle-depth of the trench for shielding a reverse leakage currentthrough the sidewalls of the trench. Then the method proceeds withanother step of implanting at substantially at a zero degree into thetrench for doping a bottom doped region of the second conductivity typesurrounding a bottom surface of the trench. Then the method follows witha step of implanting and doping a top doped region of the secondconductivity type surrounding a top portion of the sidewalls of thetrench and filling the trench with a Schottky junction barrier metal. Ina preferred embodiment, the step of opening a trench in a semiconductorsubstrate of a first conductivity type is a step of opening the trenchin a N-type semiconductor substrate and doping the middle-depth dopantregion comprising a P-dopant region. The step of opening the opening thetrench to a full trench depth is step of opening the trench to the fulldepth with non-rounded trench corners.

These and other objects and advantages of the present invention will nodoubt become obvious to those of ordinary skill in the art after havingread the following detailed description of the preferred embodiment,which is illustrated in the various drawing figures.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A to 1C are cross sectional views of Schottky diodes disclosed inprior art disclosures.

FIG. 2A and 2B are a cross sectional views of a Schottky diodes of thisinvention.

FIGS. 3 and 4 are cross sectional views of showing the diodes accordingto FIG. 2A integrated with planar and trench MOSFET device respectively.

FIGS. 5A to 5N are a serial cross sectional views for describing themanufacturing processes to manufacture a Schottky device of FIG. 2B.

DETAILED DESCRIPTION OF THE METHOD

Referring to FIG. 2A for a cross sectional view of an Schottky diode 100of this invention. The Schottky diode 100 is supported and formed in asemiconductor substrate, e.g., a N-doped silicon substrate 105. TheSchottky diode 100 includes a plurality of trenches forming a pluralityof semiconductor mesas. In the preferred embodiment as shown in FIG. 2Athe trenches are filled with Schottky barrier metal, e.g., Ti/TiN orTungsten metal 110. In another preferred embodiment (not shown), atleast a portion of vertical surface of semiconductor mesas is lined withSchottky barrier metal. For the purpose of preventing leakage currentgenerated by the reverse voltage, P-dopant regions 130 are formed on themesas surrounding the top portions of the trenches and P-dopant regions140 are formed that surrounding the bottom of the trenches.

As shown in FIG. 2A, P-dopant regions 130 are formed on the top cornersof mesas without extending over the whole top surface of mesas. Schottkyjunctions are also formed on the top surfaces of semiconductor mesasbetween the P-dopant regions 130. In another embodiment (not shown)P-dopant regions 130 extent allover the spaces between the trenches andno Schottky junctions are formed on the top surfaces. As shown in FIG.2A, P-dopant regions 140 surround the trenches lower corners and bottomsurfaces, no Schottky junctions are formed on the bottom surface. Inanother embodiment (not shown), P-dopant regions 140 are formedsurrounding only the bottom corners and Schottky junctions are formed ona portion of bottom surfaces. By forming the P-dopant regions 140surrounding the bottom corners of the trenches, the requirements forrounding the trench bottom surfaces are no longer necessary.Furthermore, the silicon utilization for current conduction is greatlyimproved and the reverse leakage current is effective prevented throughthe P-dopant regions 130 and 140 to form reverse current shield.

FIG. 2B is a cross sectional view of a Schottky diode 200 with furtherimprovement in the silicon utilization by additional trench sidewallarea of deeper trench. The Schottky diode 200 is similar to the Schottkydiode 100 except that the trenches in Schottky diode 200 are deeper.Furthermore, one or more P-dopant regions 120 distributed along thedepth of the trenches are formed surrounding the sidewalls of thetrenches. The reverse leakage current is effective prevented through theP-dopant regions 120, 130, and 140 to form reverse current shield.Furthermore, the silicon area utilization for current conduction isgreatly improved by adding more P-doping regions along the sidewall ofdeeper trenches.

The Schottky devices of FIG. 2A and 2B achieve the purpose to improvethe silicon area utilization of the junction barrier Schottky GBS) byforming the Schottky diode on the sidewall of trenches. Furthermore, aswill be further described below in FIGS. 5A to 5N, a Schottky deviceshown in FIG. 2B further achieve a purpose to reduce process complexity.The configuration shown in FIG. 2A and 2B can be manufactured bystandard processing steps as that commonly implemented for typicalMOSFET power device manufacture thus greatly reduce the production costand can be conveniently combined and integrated with a standard MOSFETdevice as that will be further described and explained below.

In this invention, the Schottky barrier diode is formed on the sidewallof the trenches. The P-type diffusion regions are formed on the sidewallof the trenches so that the depletions from the PN junctions shield theSchottky barrier from the reverse voltage. There are only two verticalSchottky surface segments are shown in FIG. 2B, but the number ofSchottky surface segments can be increased and the number of Schottkytrenches cab further increase and is only limited by the manufactureprocess. The silicon area utilization of this approach greatly exceedsthe conventional Schottky implemented with the JBS configurations asthat shown in FIGS. 1A to 1C.

Since top and bottom corners of the trenches are surrounded by p-typediffusion. Their curvature will not affect the electric field as theTMBS. The trench junction barrier controlled Schottky as shown in FIGS.2A and 2B is no longer required to have the trench corners rounded inorder to reduce the leakage. Therefore, it is not necessary to carry outa round process. Compared to the trench MOS barrier Schottky of FIG. 1C,the production cost is therefore reduced because of the simplifiedmanufacturing process.

The current invention can also be easily integrated into the PowerMOSFET technologies with minimal process complexity. FIG. 5 and FIG. 6illustrate how this Schottky be integrated into a Planar Power MOSFETand a Trench Power MOSFET technology respectively.

Referring to FIG. 3 for a planar MOSFET integrated with the trenchjunction barrier controlled Schottky as that shown in FIG. 2A. Theplanar MOSFET device 150 is supported on a substrate formed with anepitaxial layer 155. The planar MOSFET device 150 includes a trenchjunction barrier control Schottky device 100 as that shown in FIG. 2A.The MOSFET device includes body regions 130′ that may be thermaldiffused regions of the top P-dopant regions of the trench junctionbarrier controlled Schottky. The planar MOSFET device further includes asource region 160 encompassed by the body regions 130′. A planar gate170 is disposed on the top surface of the substrate padded with a gateoxide layer 175 controlling a channel formed between adjacent sourceregion 160 and body regions 130′. The trench junction barrier controlledSchottky is electrically connected to a metal contact 110′ and theplanar gate is electrically connected to a separate gate contact pad(not shown). The source and body contact of MOSFET may be providedthrough the source and body contacting the metal within the Schottkytrench. A higher concentration of body dopant region 130 may beimplanted around the Schottky diode trench to increase the concentrationof top doped region and to improve the ohmic contact of MOSFET bodyregion.

Referring to FIG. 4 for a trenched MOSFET integrated with the trenchjunction barrier controlled Schottky as that shown in FIG. 2A. Thetrenched MOSFET device 150′ is supported on a substrate formed with anepitaxial layer 155. The trenched MOSFET device 150′ includes a trenchjunction barrier control Schottky device 100 as that shown in FIG. 2A.The MOSFET device includes body regions 130 that may be thermal diffusedregions of the P-dopant regions of the trench junction barriercontrolled Schottky. The trenched MOSFET device further includes asource region 160 encompassed by the body regions 130. A trenched gate170′ is disposed in a trenched padded with a gate oxide layer 175′between two MOSFET cells controlling a vertical channel formed along thesidewall of the trenched gates 170′ between the source regions 160 and adrain disposed at the bottom of the substrate. The trench junctionbarrier controlled Schottky is electrically connected to a metal contact110′ and the planar gate is electrically connected to a separate gatecontact pad (not shown).

Referring to FIGS. 5A to 5N for a serial of side cross sectional viewsto illustrate the fabrication steps of a trench junction barriercontrolled Schottky device as that shown in FIG. 2B. In FIG. 5A, aninitial oxidation is carried out followed by applying a photoresist mask208 to perform an oxide etch to pattern a plurality of screen oxidelayer 210 on top of a semiconductor substrate 205. Referring to FIG. 5B,the photoresist mask 208 is removed followed by carrying out a boronimplant to form a plurality of P-dopant regions. In FIG. 5C, anannealing and oxidation process is performed to anneal and grow theoxidation layer 210 covering the entire top surface of the substrate. InFIG. 5D, a trench mask 212 is applied to open a plurality of etchopenings 218 in the oxide layer 210.

In FIG. 5E, a silicon etch is performed to open a plurality of trenches218 then the photoresist 218 is removed. In FIG. 5F, a boron implant atzero degree tilt is carried out and followed by a diffusion to form aplurality of P-dopant regions 220 at the bottom of the trenches 218. InFIG. 5G, a further silicon etch is carried out to etch the trenches intogreater depth leaving the P-dopant regions 220 as a ring surrounding thetrench sidewalls at about the mid-point of the trenches. In FIG. 5H, avertical zero degree boron implant is performed to form a P-dopantregions 225 surrounding the trench bottom of the trenches 218.

In FIG. 5I, a wet oxide etch is performed to broaden the trench openingby etching away a portion of the oxide layer 210 away from the trenchopenings. In FIG. 5J, a thin layer of Ti/TiN is deposited followed by atungsten layer 230 through chemical vapor deposition (CVD) process. InFIG. 5K, a Ti/TiN or tungsten etch back is carried out to remove theTi/TiN or Tungsten layer 230 from the top surface. In FIG. 5L, a contactmask is applied to remove the oxide layer 210 from the top surface abovethe trench. In FIG. 5M, a Ti/TiN/Al contact layer 240 is deposited overthe top surface, then in FIG. 5N, a metal mask (not shown) is applied toetch the metal contact layer 240 into contact segment 240 to completethe manufacture of the trench junction barrier controlled Schottkydevice of this invention.

The semiconductor device includes a Schottky diode formed a on asemiconductor mesa of a first conductivity type, wherein thesemiconductor mesa a top doped region of a second conductivity typeopposite to the first conductivity type along a top portion of asidewall. A bottom-doped region of the second conductivity type isdisposed along a bottom portion of the sidewall. A portion of thesidewall is lined with a Schottky barrier metal, extending at least froma bottom of the top doped region of second conductivity type to a top ofthe bottom doped region of second conductivity type. One or more dopantregions of the second conductivity type is disposed along the sidewalldistributed along a depth between the top doped region and the bottomdoped region and the Schottky barrier metal is completely lining thesidewall. The top doped region of the second conductivity type is formedat a top corner of the semiconductor mesa. The bottom-doped region ofthe second conductivity type is formed at least around a bottom cornerof the semiconductor mesa. The Schottky junction metal overlaying a topsurface of the semiconductor mesa forming a Schottky junction in a areabetween the top doped regions of second conductivity type. The top dopedregions are of a second conductivity type extending all over thetop-surface the semiconductor mesa and the semiconductor mesa includesnon-rounded corners. A MOSFET device is integrated with the Schottkydiode configured as a trench junction barrier Schottky (TJBS) diode, andthe MOSFET device is manufactured simultaneously with the Schottky diodeconfigured as a trench junction barrier Schottky (TJBS) diode. Thesemiconductor device further includes a planar MOSFET device integratedand manufactured simultaneously with the Schottky diode wherein theplanar MOSFET further includes a body region extending to andsurrounding a top portion of the trench of the Schottky diode forshielding a reverse leakage current through the sidewalls of the trench.In a preferred embodiment, the semiconductor device further includes atrench MOSFET device integrated and manufactured simultaneously with theSchottky diode configured as a trench junction barrier Schottky (TJBS)diode wherein the trench MOSFET further includes trenched gatesdisposing around the trench of the TJBS diode. In a preferredembodiment, the MOSFET device further includes a body region extendingto and surrounding a top portion of the trench of the Schottky diode forshielding the reverse leakage current through the sidewalls of thetrench.

According to above descriptions, this invention discloses a Schottkydiode that includes at least a trenched opened in a semiconductorsubstrate doped with a dopant of a first conductivity type wherein thetrench filled with a Schottky barrier metal. The Schottky diode furtherincludes a plurality of dopant region of a second conductivity typeopposite to a first conductivity type surrounding a sidewall of thetrench distributed along a depth of the trench for shielding a reverseleakage current through the sidewall of the trench, the plurality ofdopant region of a second conductivity type further comprising a topdoped region overlapping a top of the Schottky barrier metal and abottom doped region overlapping a bottom of the Schottky barrier metal.

Although the present invention has been described in terms of thepresently preferred embodiment, it is to be understood that suchdisclosure is not to be interpreted as limiting. Various alterations andmodifications will no doubt become apparent to those skilled in the artafter reading the above disclosure. Accordingly, it is intended that theappended claims be interpreted as covering all alterations andmodifications as fall within the true spirit and scope of the invention.

1. A Schottky diode comprising: at least a trenched opened in asemiconductor substrate doped with a dopant of a first conductivity typewherein a sidewall of said trench is lined with a Schottky barriermetal; a top doped region of a second conductivity type surrounding atop portion of said sidewalls of said trench; and a bottom doped regionof said second conductivity type surrounding at least a bottom corner ofsaid trench.
 2. The Schottky diode of claim 1 further comprising: One ormore dopant regions of said second conductivity type surroundingsidewalls of said trench distributed along a depth of said trenchbetween said top doped region and said bottom doped region.
 3. TheSchottky diode of claim 1 wherein: said trench is filled with saidSchottky barrier metal.
 4. The Schottky diode of claim 1 wherein: saidSchottky barrier metal further lining a bottom surface of said trenchforming a Schottky junction on said trench bottom surface.
 5. TheSchottky diode of claim 1 wherein: said bottom doped region of saidsecond conductivity type completely surrounding a bottom surface of saidtrench.
 6. The Schottky diode of claim 1 wherein: said Schottky barriermetal overlaying a top surface of said semiconductor substrate forming aSchottky junction with said semiconductor substrate in a area betweensaid top doped regions of second conductivity type.
 7. The Schottkydiode of claim 1 wherein: said top doped regions of second conductivitytype completely filling a space between said trenches.
 8. The Schottkydiode of claim 1 wherein: said trench comprising non-rounded trenchcorners.
 9. A semiconductor device comprising a Schottky diode formed aon a semiconductor mesa of a first conductivity type, whereas saidsemiconductor mesa comprising: a top doped region of a secondconductivity type opposite to said first conductivity type along a topportion of a sidewall; a bottom doped region of said second conductivitytype along a bottom portion of said sidewall; and wherein a portion ofsaid sidewall is lined with a Schottky barrier metal, extending at leastfrom a bottom of said top doped region of second conductivity type to atop of said bottom doped region of second conductivity type.
 10. Thesemiconductor device of claim 9 further comprising: one or more dopantregions of said second conductivity type along said sidewall distributedalong a depth between said top doped region and said bottom dopedregion.
 11. The semiconductor device claim 9 wherein: said Schottkybarrier metal completely lining said sidewall.
 12. The semiconductordevice claim 9 wherein: said top doped region of said secondconductivity type formed at a top corner of said semiconductor mesa. 13.The semiconductor device claim 9 wherein: said bottom doped region ofsaid second conductivity type formed at least around a bottom corner ofsaid semiconductor mesa.
 14. The semiconductor device claim 9 wherein:said Schottky junction metal overlaying a top surface of saidsemiconductor mesa forming a Schottky junction in a area between saidtop doped regions of second conductivity type
 15. The semiconductordevice claim 9 wherein: said top doped regions of second conductivitytype extending allover a top surface said semiconductor mesa.
 16. Thesemiconductor device claim 9 wherein: said semiconductor mesa comprisingnon-rounded corners.
 17. The semiconductor device claim 9 furthercomprising: a MOSFET device integrated with said Schottky diodeconfigured as a trench junction barrier Schottky (TJBS) diode.
 18. Thesemiconductor device of claim 9 further comprising: a MOSFET deviceintegrated with and manufactured simultaneously with said Schottky diodeconfigured as a trench junction barrier Schottky (TJBS) diode.
 19. Thesemiconductor device claim 9 further comprising: a planar MOSFET deviceintegrated and manufactured simultaneously with said Schottky diodewherein said planar MOSFET further comprising a body region extending toand surrounding a top portion of said trench of said Schottky diode forshielding a reverse leakage current through said sidewalls of saidtrench.
 20. The semiconductor device claim 9 further comprising: atrench MOSFET device integrated and manufactured simultaneously withsaid Schottky diode configured as a trench junction barrier Schottky(TJBS) diode wherein said trench MOSFET further comprising trenchedgates disposing around said trench of said TJBS diode.
 21. Thesemiconductor device claim 20 wherein: said MOSFET device furthercomprising a body region extending to and surrounding a top portion ofsaid trench of said Schottky diode for shielding said reverse leakagecurrent through said sidewalls of said trench.
 22. A method formanufacturing a Schottky diode comprising: Providing a region with adopant of a second conductivity type opposite to a first conductivitytype to form a top doped region in a semiconductor substrate of saidfirst conductivity type; providing a trench through said top dopedregion to a predetermined depth and providing a dopant of said secondconductivity type to form a bottom dopant region of said secondconductivity type; and lining a Schottky barrier metal layer on asidewall of said trench at least extending from a bottom of said topdoped region to a top of said bottom doped region.
 23. The method ofclaim 22 further comprising: Providing at lease an intermediate dopantregion of said second conductivity type surrounding a sidewall of saidtrench at a depth shallower than said predetermined depth.
 24. Themethod of claim 22 further comprising: implanting at substantially at azero degree into said trench for doping a bottom doped region of saidsecond conductivity type surrounding a bottom surface of said trench.25. The method of claim 24 further comprising: filling said trench witha Schottky barrier metal.
 26. The method of claim 22 wherein: said stepof providing a trench in a semiconductor substrate of a firstconductivity type is a step of opening said trench in a N-typesemiconductor substrate and doping said dopant region with a P-dopant.27. The method of claim 25 wherein: said step of filling said trenchwith a Schottky barrier metal comprising a step of filling said trenchwith a Ti/TiN metal.
 28. The method of claim 25 wherein: said step offilling said trench with a Schottky barrier metal comprising a step offilling said trench with a Tungsten metal.
 29. The method of the claim22 wherein: said step of opening said trench to said predetermined depthcomprising step of opening said trench to said said predetermined depthwith non-rounded trench corners.
 30. A Schottky diode comprising: atleast a trenched opened in a semiconductor substrate doped with a dopantof a first conductivity type wherein said trench filled with a Schottkybarrier metal; and a plurality of dopant region of a second conductivitytype opposite to a first conductivity type surrounding a sidewall ofsaid trench distributed along a depth of said trench for shielding areverse leakage current through said sidewall of said trench, saidplurality of dopant region of a second conductivity type furthercomprising a top doped region overlapping a top of said Schottky barriermetal and a bottom doped region overlapping a bottom of said Schottkybarrier metal.